Electrically-driven sound-reproducing machine



May 15, 1923. 1,455,262 R. MOSMANN ELECTRICALLY DRIVEN SOUND REPRODUCING MACHINE Filed March 1922 2 Sheets-Sheet 1 May 15, 1923.

R. MOSMANN ELECTRICALLY DRIVEN SOUND REPRODUCING MACHINE Filed March 1, 1922 2 Sheets-Sheet 2 72 2/612 2 01"; N Q 291 21 /zarc{ M31774??? 736.5 cam/"17 Patented May 15, 1923.

meant PATENT caries.

REINHARD MOSMANN, OF ST. GALLEN, SWITZERLAND.

ELECTRICALLY-DRIVEN SOUND-REPRODUGING MACHINE.

Application filed March 1, 1922. Serial No. 540,236.

Tana/whom it may concern."

Be it known that I, REINHAR MOSMANN, citizen of Switzerland, residing at St. Gallen, Switzerland, have invented certain new and useful Improvements in Electrically Driven" Sound-Reproducing Machines, of which the following is a specification.

The present invention has reference to improvements in sound recording and reproducing" machines with electric motor drive and relates more particularly to a motor and turntable control which is automatically actuated by the tone arm at a predetermined point for cutting off the current to the motor, for arresting the turntable and locking it against retrograde movement, and for using this locking action to momentarily brake down the motor.

My invention will best be understood 3 is a side view of the parts shown in Fig.

1; Fig. 4 is a bottom view of Fig.- 3; Fig. 5 illustrates the electric circuit employed, and Fig.6 is a plan view of control details.

. In the cabinet 3 with cover 2 is supported on cleats 4 the instrument plate 1 from the underside of which depends the frame 5 in which is mounted the electromotor 6 of any suitable construction, which by the belt 7 acting on the pulley 8 drives the turntable shaft 9. The upper end 11 of this latter is extended through the perforation 10 in the plate 1 and supportsthe turntable 12 for the reception of the disc record 13, both shown in the several figures in dash-dotted lines. For'controlling the motor speed and thus that of the turntable there is provided a suitable magnetic brake, which, forming no part of this invention, need not be specially described here, and which can be adjusted 3 bymanipulation of the knurled head 15 of the setting screw 16 of relatively steep pitch which acts onthe lever 17 fulcrumed on the bracket 14 (Figs. 1 and 4). The sound conveyer or horn 20, which communicates through the aperture 18 in plate 1 with the tone arm sleeve 21 and the tone arm proper 22, is secured to the cabinet wall preferably by interposing a sound-deadening member, The tone arm supports at its front end the sound box carrier23, which in turn supports the sound box 24 with stylus 0r needle 25. To the underside of the tone arm 22 is secured the bent-off lever arm 26 extending spacedly below the turntable in parallelism therewith, and below this arm 26 is oscillatingly pivoted on the plate 1, about the pin 28, the contact lever 27. at its free end a cam 29 extending into the path of the contact arm 26 and is influenced by the double-arm lever .31. The latter is rockingly journaled on plate 1 and is provided at its one end with a handle 30 and at its other end with a pin 32 which engages in the slot 33 in the contact leve 27 (Fig. 6). A drag spring, not shown here, may be used to advantage on lever 31 for preventing inadvertent displacement thereof after adjustment.

A brake lever 36 provided at the one end with a handle knob 35 is swingingly fulcrumed at 37 on the plate 1 and carries at its other end the brake cheek 38. A. pressure spring 39 (Fig. 2) tends to press the brake cheek against the rim of the turntable 13. Near the brake cheek 38 is pivotally secured to the lever 36 the slide or latch member 41 by means of the pin 40 which latter extends into the path of the contact arm 27, so that the lever 36 and thus the latch 41 can be operated by the handle 35 as well as by the contact arm 27 when the latter is shifted by displacement of the'tone arm 22. The latch 41 near its outer end is guided in the bracket 42 and carries at its free extremity the insulated knife contact member 43, de signed for cooperationwith the two companion spring contact members 44 and 44 The latch 41 further is provided with a notch 45 (Fig. 2), in which engages the pawl 46 upon coaction of the parts 43, 44 and 44*, thereby preventing their accidental disconnection. The pawl 46 extends through an aperture 47 in plate 1 and is rigidly secured to the armature 48 hung up in the plate bracket'49 (Fig. 4). Thearmature 48 is acted on by the electromagnet 50 and is further infiuenced by the counter-spring 57. Contact springs 51 are secured to the underside of plate 1 and coacting contact members 52 are secured in a block 53 on the near cabinet wall.

The numeral 54 designates a plug contact base and the numeral 55 a contact spring plate on plate 1 in electric contact with the tone arm sleeve 21 and with the circuit 6.

By means of the switch 56 the main circuit a and also the circuit e can be cut in or out, as required. From the contact members 52 which receive current in any suitable manner, for instance from the house lighting circuit or from a storage battery, the circuits (Fig. 5) are fed, the line a leading from the one member 51 ,direct to the motor 6, thence to the switch 56, to the resistance WV, preferably an incandescent lamp, and finally to the contact member 44, whilst line b leads from the other contact member 51 direct to the contact member 44 A branch line 0 connects the part of line a between switch 56 and lamp W with the electromagnet 50, whose other terminal line (Z is connected up to the contact lever 27 In the resistance TV the line 6 is branched off from the part of line a between W and 44 and is connected up to the contact spring 55, so that on the contact arm 26 contacting with the cam 29, in cut-in position of the switch 56 the current will pass through the magnet.

*or setting the device, the switch 56 is cut out and the needle 25 is placed on that point of the record 13, or is held just above it, where the operation of the machine is to be automatically interrupted. Next, by means of the setting lever 31 the contact lever 27 is swung around until its cam 29 contacts with the arm 26. Thecam 29 is so located and the lever 27 of such length and its fulcrum so chosen that the point of contact between arm 29 and arm 26 always lies substantially vertically below the point of contact between needle and record, which makes for a very accurate adjustment and operation of the device. The tone arm 22 is now displaced toward the brake cheek 38 until through the arm 26 and pin 40 the brake cheek is removed from the turntable 12 and the pawl 46 snaps into the notch 45 of latch 41. Thereupon the needle is let down onto the record at the desired point for starting.

If desired, the brake check 38 may first be retracted by its handle 35 from the turntable which will bring the contact knife 43 between the contact springs 44 and 44 and only then the contact members 26 and 29 would have to be brought into their end positions and finally the needle placed at the point on the record from where the latter is to be reproduced.

If now through switch 56 the circuits a and b are closed the. turntable 13, by means of the belt. 7 will be rotated from the motor latch 41. The spring 89 will now force the brake cheek 38 against the turntable and simultaneously the contact knife 43 will come free of the contact members 44 and 44", which breaks the circuit through the motor and the magnet. The motor thus loses its power andthe turntable is arrested, and this in such manner that not only a retrograde movement of the turntable is prevented but that also the momentary arrest of the turntable by the brake is used in turn to momentarily brake-down he motor through the belt or like connection 7.

After, complete arrest of the parts the switch 56 is cut out by hand. v

The control device is shown in the drawings at the stage in which the circuit through the motor for closing the circuit through the electromagnet is interrupted, with the switch 56 in on-position,

lVhat I claim is 1. In a sound reproducing machine inautomatic means for momentarily arresting the rotary machine p'arts,'comprising a main circuit for the motor, a secondary circuit in: cludingan electromagnet, adjustable contact members below said turntable actua'ble by said tone arm and adapted to control said secondary circuit, a switch common to both said circuits adapted'to be operated by said electromagnet upon closure of said secondary circuit, a brake acting on said turntable and operable on closure of said secondary circuit.

2. In a sound reproducing machine including a turntable, an electromotor, and a movable tone arm, in combination, a main circuit for the said motor including a resistance, a mechanically operated cut-out and a manually operable main switch, a secondary circuit, an electromagnet therein and a pawl armature for said magnet; an augularly bent contact arm rigidly secured to said tonearm and extending spacedly below said turntable, a slotted contact arm pivotally secured at one end to a fixed machine part, a contact cam at the free extremity of said slotted contact arm adapted to cooperate with said bent contact arm ata predeterminable op: erative stage, and ahaudledroek lever controlling said slotted contact arm; a handled said pawl armature, and means in connection spring-controlled brake lever rockingly piv- With said latch for operating said main ciroted to a fixed machine part, a brake cheek cuit cut-out, and said brake lever influence- 10 on said brake lever adapted for cooperation able for resetting by said slotted contact 5 with said turntable, a latch member fularm.

crumed on said brake cheek and presenting In testimony whereof I afiix my signature. locking means adapted to cooperate with REIN HARD MOSMANN. 

